1. Field of the Invention
The present invention relates to a compact image reading apparatus which is attached to a personal digital assistant (PDA) and reads an image.
2. Description of the Related Art
FIGS. 1A, 1B, and 1C show the configuration of a conventionally well-known compact image reading process apparatus. FIG. 1A shows a PDA 1 which has been widely used these days. The PDA 1 shown in FIG. 1A is provided with an input display device 2 formed by overlapping a touch panel, which occupies substantially the entire front side of the PDA 1, and an LCD (liquid crystal display). The input display device 2 can receive various input by an input pen 3 formed by a thin resin pole, etc. attached to the PDA 1, and can also receive various instructions by a plurality of input buttons 4 arranged below the input display device 2. Normally, the PDA 1 is provided with a card insertion slit 5 at the top. For example, a PC card and a CF card are inserted into the card insertion slit 5.
FIG. 1B shows a card type image scanner 6 which is an ultra-compact image reading apparatus used as attached to the card insertion slit 5 of the PDA 1. The card type image scanner 6 is formed by a scanning unit 7 for reading an image and a connection card unit 8. When the connection card unit 8 is inserted into the card insertion slit 5 of the PDA 1 as indicated by the arrow A shown in FIG. 1B, a compact image reading process apparatus is obtained by the PDA 1 and the card type image scanner 6 incorporated into a unit as shown in FIG. 1C.
FIG. 2A is a side view of the above mentioned image reading process apparatus, and explains the state of reading an image by the above mentioned image reading process apparatus. FIG. 2B is a block diagram showing the configuration of the card type image scanner 6 which is a component of the image reading process apparatus.
First, the PDA 1 is picked up by hand, the scanning unit 7 of the card type image scanner (hereinafter referred to simply as a scanner) 6 is directed downward as shown in FIG. 2A, the scanning unit 7 closely contacts the top surface of a read medium 9 such as paper, etc., the PDA 1 is slid in the read scanning direction indicated by the arrow B, and the scanning unit 7 can read the image on the read medium 9.
The scanning unit 7 of the card type image scanner 6 is provided with an image reading unit 71 for optically reading the image on the read medium 9 as shown in FIG. 2B, and converting the optical image data into an analog electric signal, and a transfer amount measuring unit 7-2 for measuring the amount of transfer on the read medium 9 of the image reading unit 7-1.
The connection card unit 8 of the card type image scanner 6 is provided with: an image signal processing unit 8-1 for processing an analog image signal a output from the image reading unit 7-1; a reading control unit 8-2 for drive-controlling the image reading unit 7-1 by outputting a drive signal c to the image reading unit 7-1 based on a transfer amount signal b input from the transfer amount measuring unit 7-2; and a PC card I/F (interface) unit 8-3 for communicating read data and an indication signal with the PDA 1 which is an external information processing device.
As shown in FIG. 2A, read data (image signal) read as a result of the scanning operation is output from the PC card I/F unit 8-3 of the connection card unit 8 to the PDA 1, and sequentially displayed as an image on the input display device 2 of the PDA 1. Therefore, the image data can be read with a check made by the user on the input display device 2 of the PDA 1.
The power supply of mobile information equipment such as the above mentioned PDA 1, etc. is a battery, and it is necessary to continuously use the mobile information equipment for a long time using the battery. However, batteries cannot work for a long time as expected by users, and conventional mobile information equipment often leaves much to be desired because it easily indicates battery exhaustion.
Furthermore, since a scanner is normally attached to the top of the mobile information equipment, the configuration requires picking up the mobile information equipment upside down when the scanner is operated, which sets the correspondence between the user and the mobile information equipment different from the correspondence between them in the normal use of the mobile information equipment. As a result, there has been the problem that the user feels inconvenience when the scanner is incorporated into the mobile information equipment.
Additionally, when the mobile information equipment is provided with a display device such as a liquid crystal display device, etc. as a monitor screen, the user checks a read image on the monitor screen after the image has been completely read by the scanner and a capturing device. While the image is being read, the user pays his or her attention to the reading operation, and does not carefully check the image on the monitor screen. Therefore, although it is not necessary to turn on the backlight of the display device, the backlight is unnecessarily turned on in the conventional technology, thereby accelerating the wasteful power consumption.